Field of the Invention
The present invention relates to a manufacturing method of a plugged honeycomb structure, and more particularly, it relates to a manufacturing method of the plugged honeycomb structure in which it is possible to decrease a plugging slurry to be discarded in charging the plugging slurry into cells.
Description of the Related Art
Heretofore, in cars and the like, filters (diesel particulate filters (DPF)) to trap particulate matter (PM) to be emitted from a diesel engine and the like have been used. As this filter, there is known a filter (a plugged honeycomb structure) including a honeycomb structure having porous partition walls defining a plurality of cells which become through channels for fluid, and plugging portions disposed in end portions of the cells of this honeycomb structure.
In this plugged honeycomb structure, when introducing an exhaust gas into the cells from an inlet-side end face, the exhaust gas permeates the porous partition walls to flow into adjacent cells, and a purified exhaust gas is emitted from an outlet-side end face. In this way, when the exhaust gas permeates the partition walls, dust and particulates contained in the exhaust gas are trapped in the partition walls.
Furthermore, this plugged honeycomb structure can be prepared by obtaining, by extrusion, a pillar-shaped honeycomb structure having the porous partition walls defining the plurality of cells which become through channels for the fluid, and then subjecting the honeycomb structure to a plugging step.
As an operation to be performed in the plugging step, various operations are known (e.g., see Patent Documents 1 to 3). Specifically, there is a method as follows. First, an adhesive film is attached to one end face of a honeycomb formed body, and by laser processing in which image processing is utilized, holes are made only in portions of the adhesive film which correspond to the cells to be plugged. In this way, there is performed an operation of attaching a mask to the one end face of the honeycomb formed body. Then, the one end face of the honeycomb formed body to which the mask is attached is immersed into a slurried plugging material (a plugging slurry) containing a ceramic material and stored in a container, to charge the plugging material into the cells in which the plugging portions are to be formed. Next, as to the other end face of the honeycomb formed body, the plugging material is also similarly charged into the cells in which the plugging portions are to be formed. It is to be noted that various plugging materials are also reported (e.g., see Patent Document 4).
[Patent Document 1] JP-A-2008-30469
[Patent Document 2] WO 2008-114637
[Patent Document 3] JP-A-2001-300922
[Patent Document 4] JP-A-H01-297114